Okay, these posts seem to be once again centered on energy management. although the more recent posts were related to the 110 AC portion of the RV power system, surge protection, EMS remote monitoring, these posts relate to the 12 VDC portion. Just as on the AC side just knowing the voltage level, although important does not provide enough information for overall analysis and planning. Knowing the voltage, as well as, the current (power) on the AC side enable one to determine for example what current is drawn from each device. One can then determine/plan what can be turned on and stay within the rating of your rig (basically 30 or 50 amp).

Same applies for the 12V DC side, just knowing the voltage does not provide enough information. Just like on the AC side nice to know what current is drawn from each 12V DC device. For example determining what type/size batteries do I need to install, capacity (Amp Hour). Nice to know where you are now before you plan what/where you want to do/go. Also for troubleshooting what is the current output of your converter at the various stages, etc

Knowing more than just voltage levels on either the 110V AC or 12V DC side is equally important for troubleshooting and planning involving these two RV power sources.

Yes there is a point where it is overkill (flashing lights , etc) on any thing, I think if you want to monitor power you need to know more than than voltage level. Okay stepping Down

I bought one of these, https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 and installed it into the battery lid along with a disconnect switch. That way when I turn the battery on I know what the voltage is and whether or not I need to plug in to the truck to raise the jack. This works for me as we don't dry camp.

To monitor power consumption, to manage electrical use, to "delve" into battery management, then power consumption is required.

HOWEVER, to simply know the charge status of a battery or a battery bank, all that's needed is a voltmeter. Here's all that's required to know when to plug in a charger or whether you are "good to go" until later:

12.6 100% charged
12.5 90% charged'
12.4 80% charged
12.3 70% charged and where the battery "ought to be recharged".
12.2 60% charged and where you really need to stop using power and recharge.
12.0 50% charged and at this point (on a voltage monitor) it's time to pull out the generator and start recharging the battery "fer sure"....

Most of us are "saavy enough to know" that if the battery is at 70% and we didn't make it through the night last night, we won't make it tonight either. And they know that "if the battery voltage is as 12.2, it's not going to be a "warm, well lit night".... That relationship of voltage to battery charge state is all that nearly every one of us needs relate to.

There's no "need" to have an ammeter, a shunt, a series of lights and switches, or anything but a simple "plug it in the cigarette lighter socket voltmeter" or a similar device... All the rest, for the LAYMAN who doesn't comprehend the inter-relationship of amps/volts/relationship of shunts to needle deflection/Ohms law, is more complex than they need to enjoy a dry camping trip and all they need to remember or they can post a small chart) with the above five voltage/charge state numbers and that's all that's necessary.

When you go to the "auto-level control panel", push the button and get an ERROR light or an ERROR lockout, walk inside, look at the voltmeter. If it's less than about 12.1 VDC, it doesn't much matter how many "amp-hours are remaining" or the "power consumption in amps" or the "voltage drop when the inverter comes on".... What matters, to the layman is voltage "right now" as it relates to "battery charge status "right now". all the rest is just "fluff" to the average camper owner whose understanding of electricity is "check the plug if it won't turn on" and after that, call a repairman or get on the forum and ask for help..... Those members don't need the fluff.....

For (my guess) 95% of campers, anything more than a simple digital voltmeter is "overkill"..... YMMV

LoganX I highly recommend the Trimetric 2030RV it works great monitoring the 4 6v batteries in mine. And now that you have upgraded to real batteries you need to start thinking of battery use in amps and % of battery left not volts the Trimetric tells you that and a lot more including currant amp draw and daily amp draw. You should also move to a dedicated charger intended for the 6v batteries not a automotive type or the built in charger. Also stay at or above 80% battery capacity as much as possible to prolong battery life. I have 464 amps of battery power and I can go 3 days and nights and stay at the 80% mark it then takes 3-5 hrs to recharge.

Just happen to find a picture of my simple home made Power panel for RV power Management (110V AC and 12V DC). Hopefully picture will transfer OKAY. As should be, we have differing opinions as to what and how we do things which I think is the strength of this forum.

I guess I continue to view the DC portion of the RV power system like that on the 110V AC portion. I guess If I had a choice I prefer having more data than less. I understand others may not share my opinion and may consider some solutions as "DATA OVERFLOW". Like anything else they is a cost associated with complexity. As shown in these posts alone complexity and cost vary as well as data available to the user.

My guess is the simple plug in or wire in volt meter is probably $10-15 and extremely easy to install. Other canned applications will be much more than that and require a stunt to be wired in. Weaselguys has supplied a good picture of the shunt wiring. My investment less shunt wiring time and wire to the Power Center was around $20. We all have our way to float our boat

LoganX I highly recommend the Trimetric 2030RV it works great monitoring the 4 6v batteries in mine. And now that you have upgraded to real batteries you need to start thinking of battery use in amps and % of battery left not volts the Trimetric tells you that and a lot more including currant amp draw and daily amp draw. You should also move to a dedicated charger intended for the 6v batteries not a automotive type or the built in charger. Also stay at or above 80% battery capacity as much as possible to prolong battery life. I have 464 amps of battery power and I can go 3 days and nights and stay at the 80% mark it then takes 3-5 hrs to recharge.

I just use my multi meter to check DC volts at the batteries and usually do this while outside enjoying my first cup of java and fresh morning air... Iíll check again in the evening to see state of batteries.. fire up the Hondaís to charge as needed... this is of course when boon docking

John, I assumed that you checked the voltage monitor panel against a reasonable quality voltmeter. Is it within at least 0.05 volts? If so, I agree good enough and very cost-effective. I just looked up a table that showed each 0.1 volt was about 10% of the charge.

X2 or is it X3 on the Trimetric TM2030 monitor. Thatís what I installed to monitor my 6v batteries when i upped my solar to 400 watts. It does a fantastic job of showing amp flow in and out of the batteries, battery voltage and a whole lot more. After things are set up and working properly I mostly just set it to read % of charge ( or SOC = State Of Charge).